Some considerations regarding the construction of mobile television units

The purchase of a vehicle for television broadcasting and production should be initiated at previous planning and design meetings in such a way as to involve all those who will use the mobile unit and who will control its use. A vehicle of this nature must be designed with a view to serving what it will be used for 95% of the time. The other 5% should be designed as an expansion space and for special uses that fit within the budget. When a production system works for 95% of the time of use, it can always be temporarily equipped for the other 5% during which the circumstances are either extreme or unusual. If you keep this rule, the probability of success of your design will be much higher.

There are other guidelines that should be taken into account during planning sessions. Some of the most important are:

1. How much does it weigh? Does that weight absorb too much of the payload?
2. How much energy does that weight consume? Can we get enough power from the generator?
3. Do we need all that energy for 95% of the time?
4. Do we have enough space for all that?

Once you have met with the people who will use the vehicle, with those who will control its use and with the people who are in charge of maintenance, you should obtain enough information to put together a basic list of requirements and equipment, as well as a budget that takes into account the total weight and energy costs. If you don't have all of these things, get them before you call the provider since he's going to ask for them.

It is better to leave the design and construction of ENG and SNG vehicles to the manufacturers, who have usually already built too many vehicles to have made all the possible mistakes that a television station or a private company will make when trying to build their own. Manufacturers of mobile television transmission and production units have sufficient inventories and access to appropriate components for a mobile design that withstands the heavy use that production activities will impose on vehicle systems.

If your station has specific production requirements, most manufacturers can meet them. If they can't, go to another provider. The reluctance to listen to your ideas is a sign of inflexibility that can bring you problems in the future.

It is better not to invent the wheel again. Most vehicle designs can easily accommodate current production practices. Suppliers should have different designs to choose from. If not, go with another provider. The lack of designs is a sign of inexperience.

A provider should also have a list of references that you can contact. It should show you photographs of the vehicles, in addition to the diagrams. The photographs will not only tell you what the supplier can do, but also what other stations are doing to fix production problems within the vehicles. You should be as open to the provider's ideas as he is to yours.

Manufacturers almost never make vehicles "in series". Standard designs almost always undergo modifications to fit the specific needs of stations and production companies. The test of how good a vehicle is, or how responsive a supplier is, is knowing how many customers return to it again.

If you are willing to buy a standard design, with few or minimal changes, you are likely to get a more efficient vehicle since the supplier will not have to charge you more engineering and more production time to transform the original design.

Small vehicles, such as ENG vans, are very difficult to convert to multi-purpose vehicles. The difficulty begins when using a body that has been designed and built to fulfill many purposes. Converting a multi-purpose vehicle to a specific use vehicle will take time, money and considerable engineering effort if you want to do a good job.

The most popular pickup truck for conversion to an ENG vehicle or a small EFP is the Ford E-350. And this is so if you simply look at the number manufactured for the US, Canada and Latin America. Other very popular vans are the Mercedes Vario and the Iveco Turbo Daily. All of these trucks are in a similar weight category and each has its own advantages and disadvantages. However, they all have one problem in common: a finite weight capacity that can easily be exceeded during conversion to a vehicle for mobile TV unit. All of them require a careful engineering process to avoid being above the net weight level of the vehicle.

Weight is the most difficult problem you can face during conversion. It is a problem that must be faced from the design phase and NOT during construction. If the construction phase is reached, it is already too late. An overweight vehicle is illegal in most countries. An overweight vehicle is dangerous for everyone, inside and outside it; which can mean a disadvantage for the owner. Last but not least, an overweight vehicle implies a maintenance obligation that decreases its reliability and longevity. The moral is that you should choose a vehicle with the appropriate weight capacity for the purpose. Also, charging a vehicle just below its maximum capacity is also a bad idea because anything that works at its maximum design level will wear out very soon. Always leave a wide margin of weight.

A vehicle dedicated to production is always "fattened" because no one takes away weight. We like to say that mobile units are like vacuum cleaners: They seem to suck equipment as they pass through workshops or buildings. Leftover equipment tends to "migrate" on its own to vehicles over time. You need to keep this in mind since it will always happen.

Notice how the provider uses the space. If the provider uses the available spaces wisely, that will be a good sign that they have experience in the field. If, on the other hand, you find that the use of space is inefficient for the sake of style, you may have to face an unbalanced or difficult to maintain vehicle. In that case, look for another provider. An elegant interior design with shelves placed in curved shop windows can attract attention, but always look from behind and it will be very revealing. Poor shelf access, and erratic depth, can make equipment placement a difficult if not impossible task. Remember that any design decision you make will have consequences. At every turn you'll have to weigh the consequences to determine what you're willing to stick with and what you're not.

Examine very carefully the practical use of space in conjunction with weight and balance. This problem can become the most important in terms of longevity and reliability of a mobile unit. Good engineering isn't always pretty, but it should always be practical. Simply put, form must follow function. The total weight and its distribution is the decisive factor of any modification that must be made in small trucks. When the weight capacity is increased along with the size of the truck, the weight ceases to be important. However, weight will always remain a significant factor in any design decision.

If you are going to observe a supplier's standard designs, take note of where you locate mechanical and electrical support equipment in the vehicle to save space for transmission equipment. Equipment such as hydraulic pumps to stabilize jacks, reversing batteries in sliding trays, and air compressors can be located away from shelf space and normal storage areas. Access to these devices should be very easy for maintenance and service checks. These items should be placed in protected storage compartments with proper lighting and locked doors.

The storage areas located behind the shelves should allow easy and quick access. Shelf access doors should be modular and easy to replace. You must be able to access all shelves even through exterior doors. Difficult access to a shelf can mean problems during an emergency. The possibility of constant monitoring and thermal insulation are equally important for shelf access and storage areas as they are for production areas. Have the provider describe you and show you that these problems have been resolved effectively.

Air conditioning. Small vans are a problem when it comes to achieving low temperatures. Air conditioning is the largest single consumer of energy in a truck. If you try to place several larger capacity air conditioners in a small truck, the generator must also be larger and the problem begins to grow. The simplest solution is to remember that the roof-mounted air conditioner of the unit is trying to cool a small space. To the extent that the unit normally has large side doors, each time these doors are opened the fresh air inside is exchanged with the external air and must be reconditioned again. This is a particularly acute problem in tropical and subtropical regions. The solution: Open and close the doors as little as possible.

A standard 13,500 BTU air conditioner is capable of cooling a volume of air six times the size of a pickup truck if not continuously filled with hot, moist air. In essence, the air conditioning unit in the mobile unit cannot cool the world, only to a small portion of it. If we understand that, the next step will be to put in the best possible thermal insulation. Insulation up to R-14 is now possible with the new materials. Packaged fiberglass is useless since it depends on air space to obtain an R value. Sprayed foam is expensive due to environmental regulations (it emits a cyanide gas when mixed and sprayed), and it is difficult to mold and work the foam to the appropriate contours of a curved body to a uniform thickness. Therefore, it is a material that involves a large component of labor. Finally, sprayed foam cannot ensure the R value that other insulation materials can with less cost and labor.

Insulation (Reflectix bubble-pak) with R-14 value has become the standard material for small vehicles.

The generators incorporated into the system have improved but the mobile generators are getting better every day. The most reliable generators are diesels. Outside of the U.S. and Canada, diesel fuel is cheaper than gasoline. Diesel engines use less fuel, have more torque and double in duration to gasoline engines. The same can be said for diesel vehicle engines. Diesels also operate more effectively in very hot environments and the new designs work very well even in Canadian winters. Excellent 7,8,10 and 12 kilowatt diesel generators can be obtained for use in EFP vans and small trucks. The availability of diesel fuel, of course, is a logical objection in any country.

If you prefer a gasoline engine, there are liquid and air-cooled generator engines that have a good service life but will require better maintenance, use more fuel and will not have the torque of a diesel engine. The best option is a generator motor that can be maintained locally in the destination country. The supplier must also maintain the generator of the mobile unit.

There should be easy access to the generator compartments from the outside of the vehicle through a strong grille door. Generator compartments that require or allow access from within the vehicle can cause smoke to leak from the vehicle's exhaust. This is unacceptable. Compartments should be constructed of welded aluminum and lined with good suppressor materials designed for engine compartments.

Access of changing engine fluids through the compartment floor should be provided. The engine discharge should be directed to the outside of the vehicle away from the immediate work area in such a way as to reduce noise and keep smoke away from production scenes. A washable air filter must be maintained for the entry of cooling air into the generator compartment.

All added elements (compartments, doors and door frames) must be made of welded aluminium for weight and strength reasons. Doors should have spring, gas tube or stainless cable locking mechanisms to prevent doors from opening. The compartments must have 12vdc lighting activated by the door switch and also manually to be able to turn off the light if the door is left open for long periods.

Doors should have soft rubber packaging compressed by the door frame to decrease dust and sand intrusion into the compartment. Door latches must be governed by U.S. Department of Transportation regulations with dual-phase doorknobs and common key locks.

External devices for electrical outlets must allow grounding. Connections for external electricity input must at least be marine level and built for extreme humidity environments. Power supply cables must be water resistant at both ends. For uncoated electrical wires, the cable inlet must be inserted from the bottom up into the compartment to prevent water from rushing into the connection.

When open, service doors for mechanical equipment should be able to serve as additional shelves during service activities. The compartments that house batteries and electric motors should always be ventilated to allow a wide exchange of air without the possibility of water entering. These doors should also have rubber packaging and locked locks.

The electrical system is the heart and soul of a mobile television unit. In order for it to serve effectively for the production and transmission of television, extreme care must be taken in the construction of the electrical system. All cable sizes should double the required voltage capacity. The primary insulation sheaths of the cables must be color-coded to identify their purpose in those places where the insulation color is not dictated by code. The wire enumeration must be permanent at both ends. Where possible, the purpose of the wire should be printed on the primary insulator at intervals of a few inches or centimeters. High-voltage lighting should be distributed along the truck within a flexible metal gutter. 12vdc cables must be distributed in flexible plastic pipe, approved for the use of wire channeling. Wires that pass through metal or wood must have washers to prevent abrasion of channels and insulators. Cable and wire clamps must be either made of insulating steel or aluminium or of standard wraps. Where possible and appropriate, approved UL or CSA materials should be used.

Switches, beak suppressors and electrical panel components must be governed by global standards with the corresponding approval seals. The boards must be made of aluminum with clear and visible nomenclature. The framing of the electrical board should also be aluminum with access only through a front hinge board. Cable inputs to the board framing must have safety washers. 12vdc "bus bars" must be made of high-performance copper and have insulating coatings to prevent accidental shorts. All 12vdc supplies must have in-line fuses.

All electrically fitting devices must be marine level with proven reliability under conditions of mobility. The supplier must have an inventory of these items for replacement in cases of emergency. The technical documentation of these devices must always accompany the vehicle. The placement of energy conditioning appliances must be provided so that they have good ventilation and good access to easily carry out their maintenance and check-up.

The supplier must deliver the electrical diagrams as part of a clear and understandable documentation. A complete package of diagrams must be attached to the vehicle documentation. The supplier must guarantee that he will keep a copy of the truck's electrical diagrams for at least 10 years. The supplier must provide an additional equipment kit containing switches of various sizes, lights, indicator lights and a complete list of electrical parts with the respective codes.

The supplier must be willing to provide the customer with additional spare parts with the simple order via fax.

A "ready and finished" approach is very important for each step of the conversion. Doors, frames and contoured parts must be constructed and finished with obvious and precise accuracy. This is not achieved simply with a good caulking gun. The precision required is achieved with the skill of the craftsman, evidenced in his work and in the quality finishing of the materials. The quality of the craftsman must also reach the surface of the objects. Observe behind the shelves and inside the vehicle in areas you don't normally look at. Telltale signs of a mediocre craftsman include bad paint, exaggerated putties, or metal or wood roughness. Leftover cuts of wire and insulators, damaged and scraped materials indicate a lack of attention to detail and a job poorly done.

If precautions were not taken to ensure a good appearance of materials, both inside and outside the vehicle, it is very likely that precautions have not been taken in areas that cannot be seen and that means you may have problems later on. The mobile television units that are exhibited at the fairs are always given extra care. If you observe a poor finish at a fair it is very likely that the result will be much worse once the fair has ended. Look carefully at supplier references and ask difficult questions about product quality on surfaces that can be observed and in areas that no one ever looks at. Confront the companies and customers that are in the supplier references, ask them about what they liked and what bothered them. Tell the provider the results of your inquiry. Tell them what you expect for your company's money.

In essence, a mobile TELEVISION unit is an integrated system that should be built with the highest quality materials and the best workmanship. However, it must also be built so that it can be easily maintained and repaired for many years. A typical mobile TV unit must have a lifespan of at least 10 years. Most can last longer with proper care and constant and permanent maintenance. A supplier must be able to demonstrate the longevity of their product with references. You should also be able to tell you how a vehicle has improved over the years and why those older vehicles can be maintained.

Vendor information should include a detailed description of the equipment included and descriptions of the facilities and, in some cases, the reasons why the equipment is used. The vehicle proposal should be well organized into suitable categories for easy understanding that allows comparison. Good and experienced manufacturers spend a lot of engineering time and a lot of money to develop a vehicle that performs as expected. That effort should be reflected in the proposal. A simple list of equipment should not be acceptable.

The manufacturer of a mobile television unit must describe in theory and practice how he understands the common problems of mobile television transmission and production. Although smaller vehicles have many problems similar to those of their larger relatives, the circumstances are very different for an Electronic News Gathering (ENG) fast vehicle than for a sports production truck. The supplier must demonstrate an understanding of these problems in their proposal, in their references and in the engineering concept they present to meet their needs.

The best mobile unit manufacturers have a respectable experience, demonstrated by years of presence in the business, by the breadth of customers and by current vehicle orders. However, experience can also be demonstrated by their willingness to consider specific demands as well as by their good judgment for not wanting to do something that time has shown to be unfeasible. Although technology is constantly improving, it does not always reach a level of industrial production until some time has passed through the purgatory of use and practice. Switches, devices and electronic gizmos never make it to mobile units because they are designed for a non-mobile and less demanding environment. Don't be surprised if a supplier says "no" to something you'd like to see on your truck. An experienced manufacturer will have a good reason for saying "no" and should be willing to tell you.

The bottom line should be to remind you that buying a new mobile TV unit involves engaging an aggressive planning process as a customer. This planning will prepare you to provide the best information to the suppliers to whom you plan to present your project. Even though experienced unit manufacturers are able to help you design a mobile system, they can do their best work better if you know what you need, what you want, and what you can afford. It will be your vehicle, so it must be built to suit your needs.

Bob King, International Sales Manager, Frontline Communications Corp.

www.frontlinecomm.com

Email: [email protected]